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  larvae 
  from 
  which 
  he 
  obtained 
  examples 
  of 
  Bacillus 
  bombycis, 
  the 
  

   number 
  of 
  larvae 
  suffering 
  from 
  this 
  disease 
  (flacherie) 
  being 
  consider- 
  

   able 
  in 
  the 
  wet 
  summer 
  of 
  1903. 
  

  

  Coming 
  to 
  the 
  remedies 
  the 
  author 
  divides 
  them 
  into 
  two 
  groups 
  — 
  

   mechanical 
  remedies, 
  more 
  or 
  less 
  connected 
  with 
  the 
  methods 
  of 
  soil 
  

   cultivation, 
  and 
  chemical 
  remedies. 
  In 
  order 
  to 
  destroy 
  the 
  eggs 
  

   which 
  have 
  been 
  laid 
  in 
  the 
  spaces 
  between 
  the 
  rows, 
  and 
  also 
  the 
  

   larvae, 
  he 
  suggests 
  hoeing 
  the 
  surface 
  so 
  as 
  to 
  make 
  the 
  soil 
  friable, 
  

   and 
  gives 
  a 
  table 
  showing 
  the 
  satisfactory 
  results 
  of 
  this 
  method. 
  

   In 
  order 
  to 
  destroy 
  the 
  wintering 
  specimens 
  autumn 
  ploughing 
  of 
  the 
  

   fields 
  to 
  a 
  depth 
  of 
  8-10 
  inches 
  is 
  recommended, 
  thus 
  exposing 
  the 
  

   beetles 
  to 
  the 
  weather. 
  The 
  author 
  is 
  also 
  of 
  opinion 
  that 
  the 
  fields 
  

   ought 
  to 
  be 
  left 
  fallow 
  instead 
  of 
  using 
  them, 
  as 
  is 
  now 
  done, 
  for 
  summer 
  

   crops 
  ; 
  he 
  further 
  recommends 
  the 
  use 
  of 
  mineral 
  manure, 
  and 
  a 
  

   reduction 
  in 
  the 
  size 
  of 
  the 
  plots 
  so 
  that 
  they 
  can 
  be 
  better 
  protected 
  

   by 
  surrounding 
  trenches. 
  These 
  trap 
  trenches 
  usually 
  have 
  a 
  width 
  

   and 
  depth 
  of 
  14 
  inches, 
  with 
  smooth 
  walls, 
  that 
  next 
  to 
  the 
  plot 
  having 
  

   an 
  inclination 
  of 
  30° 
  ; 
  along 
  the 
  bottom 
  of 
  the 
  trench 
  holes 
  about 
  

   8-9 
  inches 
  deep 
  are 
  made 
  at 
  intervals. 
  The 
  beetles 
  that 
  are 
  trapped 
  

   must 
  be 
  collected 
  daily 
  and 
  destroyed 
  by 
  burning 
  or 
  with 
  boiling 
  

   water. 
  In 
  order 
  to 
  facilitate 
  the 
  detention 
  of 
  the 
  beetles 
  the 
  use 
  of 
  

   various 
  sticky 
  substances 
  is 
  recommended 
  ; 
  these 
  should 
  be 
  smeared 
  

   over 
  straw, 
  which 
  is 
  put 
  into 
  the 
  holes 
  in 
  the 
  trenches, 
  and 
  sticky 
  

   strings 
  may 
  be 
  placed 
  along 
  the 
  channels. 
  The 
  best 
  material 
  is 
  Tree 
  

   Tanglefoot, 
  but 
  the 
  author 
  gives 
  also 
  a 
  recipe 
  for 
  an 
  adhesive, 
  which 
  

   he 
  recommended 
  in 
  1904. 
  About 
  7 
  lb. 
  of 
  crude 
  naphtha 
  is 
  heated 
  

   to 
  the 
  boiling 
  point, 
  after 
  which 
  about 
  8 
  lb. 
  of 
  resin 
  is 
  gradually 
  

   added. 
  This 
  adhesive 
  is 
  most 
  effective 
  at 
  a 
  temperature 
  of 
  20° 
  R. 
  

   (77^ 
  F.) 
  ; 
  in 
  the 
  sun 
  at 
  a 
  higher 
  temperature 
  it 
  melts, 
  so 
  that 
  the 
  

   proportion 
  must 
  be 
  altered 
  to 
  one 
  of 
  8 
  lb. 
  of 
  resin 
  to 
  6 
  lb. 
  of 
  crude 
  

   naphtha. 
  This 
  mixture 
  can 
  also 
  be 
  smeared 
  over 
  small 
  boards, 
  which 
  

   are 
  put 
  into 
  the 
  trench. 
  The 
  use 
  of 
  small 
  tin 
  vessels 
  sunk 
  in 
  the 
  floor 
  

   of 
  the 
  trench 
  is 
  also 
  recommended, 
  as 
  they 
  require 
  less 
  attention, 
  and 
  

   when 
  full 
  can 
  be 
  easily 
  emptied 
  and 
  replaced. 
  All 
  these 
  practical 
  

   matters 
  are 
  dealt 
  with 
  in 
  detail 
  by 
  the 
  author 
  and 
  are 
  accompanied 
  

   and 
  illustrated 
  by 
  various 
  tables 
  and 
  figures. 
  

  

  An 
  account 
  is 
  then 
  given 
  of 
  sprayers 
  of 
  different 
  kinds 
  which 
  can 
  

   be 
  used 
  either 
  on 
  special 
  trap 
  zones 
  or 
  over 
  the 
  whole 
  plantation. 
  

   These 
  zones 
  are 
  useful 
  so 
  long 
  as 
  the 
  insects 
  move 
  on 
  foot, 
  but 
  must 
  

   be 
  abundantly 
  sprayed 
  with 
  strong 
  insecticides 
  ; 
  later 
  on 
  it 
  is 
  neces- 
  

   sary 
  to 
  spray 
  the 
  whole 
  of 
  the 
  plantation. 
  Barium 
  chloride 
  and 
  

   Schweinfurt 
  green 
  are 
  considered 
  to 
  be 
  the 
  best 
  insecticides. 
  The 
  

   former 
  is 
  more 
  effective 
  during 
  hot 
  weather, 
  which 
  the 
  author 
  attri- 
  

   butes 
  to 
  the 
  influence 
  of 
  the 
  sun's 
  rays 
  on 
  the 
  beetles. 
  He 
  describes 
  

   some 
  of 
  his 
  experiments, 
  which 
  have 
  shown 
  that 
  when 
  exposed 
  to 
  the 
  

   rays 
  of 
  the 
  sun 
  the 
  beetles 
  perish, 
  even 
  when 
  they 
  have 
  not 
  been 
  pre- 
  

   viously 
  poisoned. 
  The 
  effect 
  of 
  barium 
  chloride 
  is 
  to 
  produce 
  paralysis 
  

   of 
  the 
  legs, 
  which 
  prevents 
  the 
  beetles 
  from 
  taking 
  shelter 
  from 
  the 
  

   sun 
  underneath 
  leaves, 
  where 
  they 
  normally 
  hide 
  during 
  the 
  hot 
  hours. 
  

   In 
  wet 
  weather 
  the 
  effect 
  of 
  this 
  insecticide 
  is 
  not 
  so 
  great 
  and 
  

   sometimes 
  it 
  is 
  quite 
  useless. 
  " 
  Djipsin 
  " 
  and 
  Scheele's 
  green 
  are 
  not 
  

   so 
  effective 
  as 
  the 
  two 
  first-named 
  insecticides, 
  which 
  may 
  also 
  be 
  

   ccmbined. 
  

  

  